Suspension system

ABSTRACT

A trailer is supported at each side by a vehicle wheel and the vehicle wheel is mounted on a stub axle portion of a shaft, the shaft being transversely supported along its length on the frame side. Each supported section of the shaft is pivotally supported through lugs which are secured to the side of the frame. The said support for the shaft includes two bellcrank levers one disposed at each side of the frame siderail and having a spring connection which yieldably opposes movement of the wheel in a vertical direction. The wheel is thus cushioned. The wheel is supported against turning except vertically and rotatably. Other movements relative to the frame are resisted by reason of the support for the shaft which is provided at spaced points along the length thereof. Thus, the wheel is stably mounted.

[ Jan. 22, 1974 SUSPENSION SYSTEM Prima'ry Examiner-:Philip Goodhai'n[75] Inventor: Silvano Giuseppe Lievore, Elkhart, Attorney Agent orFirmjohn Young Ind.

ABSTRACT [73] Assignee: Elkhart, Bridge & Iron, Inc.,,

Elkhart, Ind.

A trailer is supported at each side by a vehicle wheel and the vehiclewheel is mounted on a stub axle por- [22] Filed: Dec. 14, 1972 Appl.No.: 315,123

tion of a shaft, the shaft being transversely supported along its lengthon the frame side. Each supported section of the shaft is pivotallysupported through lugs which are secured to the side of the frame. Thesaid support for the shaft includes two bellcrank levers one disposed ateach side of the frame siderail and having a spring connection whichyieldably opposes movement of the wheel in a vertical direction. Thewheel is thus cushioned. The wheel is supported against turn- MO J 0 662 ,0 /11A1 m ZWw 9 ,4 A R2 4 0H AAU 0 n mn 0 1% 2 m mmr. "e Us L "f C .wU.mF ii] 2 8 555 [ll [56] References Cited UNITED STATES PATENTS ingexcept vertically and rotatably. Other movements relative to the frameare resisted by reason of the sup- 267/20 R port for the shaft which isprovided at spaced points along the length thereof. Thus, the wheel isstably mounted.

8 Claims, 8 Drawing Figures 2,872,210 2/1959Shaffer.............................. 3,400,947 9/1968 Cottrill.........

SUSPENSION SYSTEM BACKGROUND OF THE INVENTION In the trailerconstruction art provision must be made for adequate suspension for thetrailer otherwise it tends to become unstable and the load carried bythe trailer is in jeopardy of damage. Not only is it important that thetrailer be stabilized for a good and efficient ride, but such is furtherimportant, insofar as it affects the steerability and track of thetowing vehicle. Unfortunately, too little attention has been paid tosuspension systems for the chassis of trailers and hence the art at thepresent time is lacking a stable and reliable suspension system fortrailers and the like.

With a two wheel trailer suspension system, such as commonly found inlight service trailers, it becomes even more important to stabilize thetwo wheels of the trailer because of the more limited ground supportafforded between the ground and the trailer.

Quite obviously, with the advent of substantial increases in the numberof boats and other recreational devices, the usage of two wheel trailersis on the increase and is projected to increase at an even faster ratein the years ahead. Since many of these trailers are towed byinexperienced drivers it is essential to improve the suspension systemin order to prevent the occurrence of accidents which can produce damageto property and compromise the safety of the driver.

OBJECTS OF THE INVENTION It is a foremost object of the presentinvention to provide a novel suspension system for trailers and the likewhichwill improve the stability of the ride of the vehicle and isespecially adapted for improving the cushioning and lateral support forthe wheel during use.

Another object of the present invention is to provide a wheel mountingwhich provides resilient support against road shock while at the sametime supporting the wheel in a stable position laterally of the frame.That is, the wheel is prevented from wobbling but is free to moverotatably and vertically but in no other direction. Consequently animportant feature of the present invention is the stable yet cushionedride for the trailer load.

Another important object'of the present invention is the provision of aninexpensive and simple suspension system which is easy to provide andrelatively easy to service, consisting of only a few componentsadditional to the conventional frame, and is readily susceptible to theinclusion of a disc brake or the like, for even further safety inhauling freight or other loads on the trailer Other objects and featuresof the present invention will become apparent from aconsideration of thefollowing description which proceeds with reference to the accompanyingdrawings wherein a single example embodiment of the invention has beenselected to illustrate the invention.

- DRAWINGS FIG. I is an isometric view of a trailer illustrating theframe and wheels of a suspension system;

FIG. 2 is a side elevation view looking in the direction of the arrows22 in FIG. 1;

FIG. 3 is a top view of the wheel and suspension system the wheel beingthe righthand wheel looking in the direction of the forward end of thetrailer;

FIG. 4 is an enlarged sectional detail view taken on line 44 in FIG. 3;

FIG. 5 is an enlarged detail view looking in the direction of the arrows55 in FIG. 3; and,

FIGS. 6 and 7a, 7b are fragmentary detail views showing details of thespring construction and stop.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. I a trailerdesignated generally by reference numeral 10 includes a frame 12 havingside rails 14 and I6 with cross braces 18, 20, 22 and 24, forming aboxlike rigid construction. In the vicinity of ground engaging wheels 26and 28 are second reinforcement members 30, 32 which reinforce siderails 14 and 16 at the location where the supportive load is transmittedto the frame. In addition, there is a further cross member 36 which issecured to depending lugs 38 and 40. Each wheel 26, 28 is rotatablymounted on an axle 46 which includes an integral laterally offsetsection 48 which in turn is connected to a shaft 50.

The shaft 50 is mounted on a link 52 and two bellcrank levers 54 and 56one on each side of rails 14 and 16. Links 52 and each of the pairs ofbellcrank levers 54, 56 are pivotally mounted on the frame, the link 52being mounted through a pivot pin 55, and plate 56 to cross member- 36(FIG. 3) and the bellcranks being each mounted on pivot pins 60, 62 ofdepending lugs 38, 40 on the outboard and inboard sides of the side ofthe frame. In this way, the wheel axle and shaft 50 are free to moveangularly about the respective pivot points 54, 60 and 62.

At the upper end 61 of each bellcrank lever is a rod 63 having athreaded end 64 and nuts 66 which secure the end of the rod to a helicalspring 68. At the opposite end 70 ofeach helical spring 68 is a secondrod 72 similarly attached to the end of the spring and also having athreaded end 74 with a nut 76 securing the spring to flange 78. Itshould be noted that a spring is located one on each side of therespective rails l4, l6 and the spring is stretched responsively tovertically upward movement of the wheel. Thus, as the bellcrank 54 (FIG.2) moves counterclockwise on the pivot 60 by upward movement of thewheel on 46, the spring 68 is stretched from its relaxed position shownin FIG. 2, the spring being held at its opposite ends by flanges 71 ofrods 63 and 72 (FIG. 6). Since there is a spring 68 located one on eachside of a respective side rail, this will cause greater stability inresilient cushioning of the wheel and without imposing a twisting actionon the wheel as it moves. The wheel is thus reliably damped againstvertical movement and is resiliently cushioned against road shocks in avertical manner.

It will be further noted that wheel movement in a vertical sense duringthe very first increment of such vertical movement, results inangularmovement of the bellcrank which is immediately opposed by tensionof the spring 68. Thus, for each increment of vertical movement of thewheel there is a corresponding increment of spring resistance forcewhich is in direct proportion to the amount of vertical displacement ofthe wheel.

The stretching of the spring to resist the vertically upward movement ofthe wheel also serves to restore the wheel to its original position.

The construction of the suspension system is cal load. Because thesuspension system consists of a few number of components which arereadily accessible for servicing the system is inexpensive to installand to keep in proper working order.

Tension on the springs is adjustable by reason of the nuts 66 and 76which can be used to elongate the spring and hence change the springrate according to the particular design of the spring and size of thetrailer.

In previous suspension systems employing springs and other cushioningdevices the resistance to vertical movement of the wheel developedobjectionable twisting actions on the wheel and tire and in still otherdevices the resilient suspension means would fail to develop aresistance which was at all times proportional to the degree of verticalmovement of the wheel. Both of those deficiencies are corrected in thepresent invention because of the presence of the spring one on each sideof a respective frame member. Also, since the spring force is directedalong the length of the spring and the bellcrank effects elongationwhich is substantially at all times proportional to the degree of wheelmovement, the wheel is cushioned with a spring force proportional at alltimes to the extent of vertical displacement of the wheel.

The spring force does not impose twisting or distorting loads on theaxle or the wheel and therefore will have less tendency to distort thewheel position and to fight" vertical movement of the wheel in avertical sense. As a result the wheel, axle and axle shaft are preventedfrom moving except in a prescribed manner and such movements are notaccompanied by objectionable extraneous twisting forces which areunrelated to normal wheel movements. In the foregoing respects theinvention has efficiently carried out its purposes.

Referring to FIGS. 7a and 7b, the bellcranks 54, 56 are limited inangular movement during downward movement of the wheel by engagement ofabutments 82 with surfaces 84 of plates 86 welded at 88 to lugs 40, 41(FIG. 3). Thus the wheels are limited in the amount of drop-off intochuckholes or the like. The described dropping action of the wheelcorresponds to counterclockwise movement of the bellcranks 56 (FIG. 7a)to the maximum downward position of 7b at which point the wheel is atits maximum downward position.

Although the present invention has been illustrated and described inconnection with a few selected example embodiments, it will beunderstood that these are illustrative of the invention and are by nomeans restrictive thereof. It is reasonably to be expected that thoseskilled in this art can make numerous revisions and adaptations of theinvention and it is intended that such revisions and adaptations will beincluded within the scope of the following claims as equivalents of theinvention.

What I claim is:

I. In a suspension system for vehicles, a frame, a mounting lug disposedone at each side of the frame members at the lateral portions of theframe, a bellcrank pivotally mounted on said lugs, an axle and axleshaft adapted to receive a vehicle wheel thereon and secured to saidbellcranks at spaced portions at the inboard and outboard sides of arespective frame side, the upwardly projecting ends of each of saidbellcranks being substantially horizontally movable during the firstincrement of angular movement, and spring means operatively connected tosaid upright portion and adapted to yieldably resist movement of thewheel in a vertical direction by the combined resistance of saidresilient means.

2. A suspension system in accordance with claim 1 including means forreceiving and supporting the pair of resilient members whereby relativemovement of said bellcrank lever is opposed by a relatively constantform in each increment of movement by said bellcrank levers.

3. The apparatus in accordance with claim 1 including a cross memberextending between and secured to its opposite end one to each of arespective side member of said frame to hold said frame rigidlytogether.

4. The frame construction in accordance with claim 3 including two coilsprings one connected to each of a respective pair of rods whereby saidrods act against the spring force of opposite ends of said spring.

5. A frame construction in accordance with claim 1 wherein said axle isstepped and includes a stub axle portion adapted to receive the wheeland the remainder portions of the axle is supported at spaced points bysaid bellcranks.

6. A suspension system for trailers and the like having a frame and twolaterally spaced side rails, said suspension system comprising a stubaxle, a laterally offset shaft, two bellcranks disposed one on each sideof a respective side rail and secured to said shaft, means secured tothe end of said axle shaft, and means forming pivot connections betweensaid frame and each of the bellcranks and said mounting means wherebysaid axle shaft and bellcranks are jointly pivoted to provide verticalmovement of said axle and axle shaft, resilient spring means disposedone on each side of a respective side rail and secured operatively tosaid frame, and at the opposite ends to a respective one of saidbellcranks to resist yieldably pivotable movement of said bellcrankswhereby vertical movement of said shaft is yieldably opposed by forcewhich is proportional to the degree of vertical movement.

7. The suspension system in accordance with claim 6 and means forming astop to limit the pivotable movement of aid bellcranks relatively tosaid frame.

8. The suspension system in accordance with claim 6 wherein saidbellcranks and mounting means disposed at the end of said shaft arespaced apart and proportioned to preclude twisting of the shaft andlimit movement thereof to angular movement about the pivot connectionsbetween said bellcranks, mounting means, and

their respective pivot connections to said frame.

1. In a suspension system for vehicles, a frame, a mounting lug disposedone at each side of the frame members at the lateral portions of theframe, a bellcrank pivotally mounted on said lugs, an axle and axleshaft adapted to receive a vehicle wheel thereon and secured to saidbellcranks at spaced portions at the inboard and outboard sides of arespective frame side, the upwardly projecting ends of each of saidbellcranks being substantially horizontally movable during the firstincrement of angular movement, and spring means operatively connected tosaid upright portion and adapted to yieldably resist movement of thewheel in a vertical direction by the combined resistance of saidresilient means.
 2. A suspension system in accordance with claim 1including means for receiving and supporting the pair of resilientmembers whereby relative movement of said bellcrank lever is opposed bya relatively constant form in each increment of movement by saidbellcrank levers.
 3. The apparatus in accordance with claim 1 includinga cross member extending between and secured to its opposite end one toeach of a respective side member of said frame to hold said framerigidly together.
 4. The frame construction in accordance with claim 3incluDing two coil springs one connected to each of a respective pair ofrods whereby said rods act against the spring force of opposite ends ofsaid spring.
 5. A frame construction in accordance with claim 1 whereinsaid axle is stepped and includes a stub axle portion adapted to receivethe wheel and the remainder portions of the axle is supported at spacedpoints by said bellcranks.
 6. A suspension system for trailers and thelike having a frame and two laterally spaced side rails, said suspensionsystem comprising a stub axle, a laterally offset shaft, two bellcranksdisposed one on each side of a respective side rail and secured to saidshaft, means secured to the end of said axle shaft, and means formingpivot connections between said frame and each of the bellcranks and saidmounting means whereby said axle shaft and bellcranks are jointlypivoted to provide vertical movement of said axle and axle shaft,resilient spring means disposed one on each side of a respective siderail and secured operatively to said frame, and at the opposite ends toa respective one of said bellcranks to resist yieldably pivotablemovement of said bellcranks whereby vertical movement of said shaft isyieldably opposed by force which is proportional to the degree ofvertical movement.
 7. The suspension system in accordance with claim 6and means forming a stop to limit the pivotable movement of aidbellcranks relatively to said frame.
 8. The suspension system inaccordance with claim 6 wherein said bellcranks and mounting meansdisposed at the end of said shaft are spaced apart and proportioned topreclude twisting of the shaft and limit movement thereof to angularmovement about the pivot connections between said bellcranks, mountingmeans, and their respective pivot connections to said frame.